Currently, computer networks have become very widespread . Using them, users can work with the same resources, programs, data, without leaving their own workplace.
What is a LAN?
The most common type of network is local area network.
A LAN is a computer network connecting local machines of users located at some distance from each other. Although the range of such a network reaches several kilometers, it is usually used to connect computers over a short distance. As a rule, these are working machines of one enterprise or home personal computers.
LAN configuration
By configuration, it is possible to mark local networks with server management and without it (equal rights).
Peer-to-peer LANs
In such networks, all computers are similar in technical specifications. Peer-to-peer LAN is a local area network in which each workstation can perform all available functions of both the client and server. For efficient load balancing in such a LAN, the number of participating computers cannot be more than 10. Otherwise, the performance of the entire network suffers.
Networks with server management (multilevel)
In such LANs, one of the computers is characterized by better performance, memory capacity and other indicators. Such a PC is assigned by the server. Servers on a LAN are computers with high performance and high memory capacity compared to user local machines. It is he who provides the interaction of other computers in the network, stores publicly accessible files and organizes access to them, transfers data to the client in the form of information for processing or the final result. LANs in which a server is used only to host shared data are called networks with a dedicated file server. Along with such systems, there are LANs in which information processing is also performed on the server , and the client receives only the result. These are the so-called client-server systems.
LAN Topology
All computers in the network at the physical level are interconnected. A LAN topology is a way to connect local machines. Now in local networks such connection methods as bus, star and ring are used.
Bus topology
In the LAN, the installation of which is planned according to this topology, a single cable is used during the assembly, to which the user's local computers are connected. Thus, information from one machine passes through all the others. The workstation to which the data is addressed selects the necessary information from the general stream.
Advantages of a LAN bus topology:
- failure of one of the local computers does not affect the operation of other machines and the network as a whole;
- Relatively simple LAN setup and design
- relatively low cost of consumables (with a small radius of action, for example, within the same organization).
Topology disadvantages:
- cable damage blocks the network as a whole;
- limited range and a small number of users;
- Relatively low performance (depending on the number of computers on the network).
Star topology
A topology of this kind involves the interaction of local computers through network equipment (a hub or hub), which provides parallel connection of working machines. Each station is connected to the central unit via a network card with a separate cable. As in the previous type of topology, outgoing data is available for all computers on the network and is accepted only by the user for whom it is intended.
Topology Benefits:
- ease of organizing a new workplace;
- high performance;
- quick troubleshooting or cable breaks;
- network operation is not affected by malfunctions of individual local machines.
Topology disadvantages:
- failure of the central device stops the entire network;
- the number of users is limited by the number of ports of the central device;
- uneconomical cable consumption;
- the cost of acquiring a hub (or other network equipment).
Ring topology
LANs, the installation of which is carried out according to the rules of this type of topology, consist of sequentially interconnected working machines that form a ring. Data in this case passes from one computer to another and stops at the one to which it is addressed.
Advantages of the “ring” topology:
- there are no costs for network equipment (hub, router);
- the ability to transfer information to multiple computers at the same time.
Topology disadvantages:
- the speed of the entire network depends on the speed of each computer;
- when a cable is broken or one computer fails, the entire network is blocked;
- complexity of setup and configuration;
- the organization of a new workplace temporarily paralyzes the work of the LAN.
The “ring” topology is practically not applied in practice due to general unreliability, but it undergoes various modifications.
Currently, virtually no organization can do without a LAN. Star network topologies are more common because of their reliability and fault tolerance. On the contrary, LANs of the “ring” topology do not meet modern performance and safety indicators. However, LANs as a whole have firmly entered our lives and contribute to the effectiveness of any enterprise.